Final answer:
The myxovirus causes mumps, not measles, irritable bowel syndrome, or infectious mononucleosis. Measles is caused by the measles virus (MeV), and infectious mononucleosis is typically caused by Epstein-Barr or cytomegalovirus.
Step-by-step explanation:
The myxovirus causes mumps, which is an infectious disease characterized by swelling of the parotid glands. It is not responsible for causing measles, irritable bowel syndrome, or infectious mononucleosis. Measles, or rubeola, is a highly contagious disease caused by a different virus, known as the measles virus (MeV), and is notable for its characteristic rash and potential complications such as meningococcal disease. Infectious mononucleosis, on the other hand, is commonly caused by the Epstein-Barr virus (HHV-4) or cytomegalovirus (HHV-5), and is spread through direct contact with body fluids such as saliva.